summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/traps.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/traps.c')
-rw-r--r--arch/powerpc/kernel/traps.c165
1 files changed, 82 insertions, 83 deletions
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 0d4e203fa7a..dcc6f159fd9 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -32,6 +32,7 @@
#include <linux/kprobes.h>
#include <linux/kexec.h>
#include <linux/backlight.h>
+#include <linux/bug.h>
#include <asm/kdebug.h>
#include <asm/pgtable.h>
@@ -173,7 +174,7 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
* generate the same exception over and over again and we get
* nowhere. Better to kill it and let the kernel panic.
*/
- if (current->pid == 1) {
+ if (is_init(current)) {
__sighandler_t handler;
spin_lock_irq(&current->sighand->siglock);
@@ -534,34 +535,40 @@ static void emulate_single_step(struct pt_regs *regs)
}
}
-static void parse_fpe(struct pt_regs *regs)
+static inline int __parse_fpscr(unsigned long fpscr)
{
- int code = 0;
- unsigned long fpscr;
-
- flush_fp_to_thread(current);
-
- fpscr = current->thread.fpscr.val;
+ int ret = 0;
/* Invalid operation */
if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
- code = FPE_FLTINV;
+ ret = FPE_FLTINV;
/* Overflow */
else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
- code = FPE_FLTOVF;
+ ret = FPE_FLTOVF;
/* Underflow */
else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
- code = FPE_FLTUND;
+ ret = FPE_FLTUND;
/* Divide by zero */
else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
- code = FPE_FLTDIV;
+ ret = FPE_FLTDIV;
/* Inexact result */
else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
- code = FPE_FLTRES;
+ ret = FPE_FLTRES;
+
+ return ret;
+}
+
+static void parse_fpe(struct pt_regs *regs)
+{
+ int code = 0;
+
+ flush_fp_to_thread(current);
+
+ code = __parse_fpscr(current->thread.fpscr.val);
_exception(SIGFPE, regs, code, regs->nip);
}
@@ -727,54 +734,9 @@ static int emulate_instruction(struct pt_regs *regs)
return -EINVAL;
}
-/*
- * Look through the list of trap instructions that are used for BUG(),
- * BUG_ON() and WARN_ON() and see if we hit one. At this point we know
- * that the exception was caused by a trap instruction of some kind.
- * Returns 1 if we should continue (i.e. it was a WARN_ON) or 0
- * otherwise.
- */
-extern struct bug_entry __start___bug_table[], __stop___bug_table[];
-
-#ifndef CONFIG_MODULES
-#define module_find_bug(x) NULL
-#endif
-
-struct bug_entry *find_bug(unsigned long bugaddr)
-{
- struct bug_entry *bug;
-
- for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
- if (bugaddr == bug->bug_addr)
- return bug;
- return module_find_bug(bugaddr);
-}
-
-static int check_bug_trap(struct pt_regs *regs)
+int is_valid_bugaddr(unsigned long addr)
{
- struct bug_entry *bug;
- unsigned long addr;
-
- if (regs->msr & MSR_PR)
- return 0; /* not in kernel */
- addr = regs->nip; /* address of trap instruction */
- if (addr < PAGE_OFFSET)
- return 0;
- bug = find_bug(regs->nip);
- if (bug == NULL)
- return 0;
- if (bug->line & BUG_WARNING_TRAP) {
- /* this is a WARN_ON rather than BUG/BUG_ON */
- printk(KERN_ERR "Badness in %s at %s:%ld\n",
- bug->function, bug->file,
- bug->line & ~BUG_WARNING_TRAP);
- dump_stack();
- return 1;
- }
- printk(KERN_CRIT "kernel BUG in %s at %s:%ld!\n",
- bug->function, bug->file, bug->line);
-
- return 0;
+ return is_kernel_addr(addr);
}
void __kprobes program_check_exception(struct pt_regs *regs)
@@ -782,19 +744,8 @@ void __kprobes program_check_exception(struct pt_regs *regs)
unsigned int reason = get_reason(regs);
extern int do_mathemu(struct pt_regs *regs);
-#ifdef CONFIG_MATH_EMULATION
- /* (reason & REASON_ILLEGAL) would be the obvious thing here,
- * but there seems to be a hardware bug on the 405GP (RevD)
- * that means ESR is sometimes set incorrectly - either to
- * ESR_DST (!?) or 0. In the process of chasing this with the
- * hardware people - not sure if it can happen on any illegal
- * instruction or only on FP instructions, whether there is a
- * pattern to occurences etc. -dgibson 31/Mar/2003 */
- if (!(reason & REASON_TRAP) && do_mathemu(regs) == 0) {
- emulate_single_step(regs);
- return;
- }
-#endif /* CONFIG_MATH_EMULATION */
+ /* We can now get here via a FP Unavailable exception if the core
+ * has no FPU, in that case the reason flags will be 0 */
if (reason & REASON_FP) {
/* IEEE FP exception */
@@ -808,7 +759,9 @@ void __kprobes program_check_exception(struct pt_regs *regs)
return;
if (debugger_bpt(regs))
return;
- if (check_bug_trap(regs)) {
+
+ if (!(regs->msr & MSR_PR) && /* not user-mode */
+ report_bug(regs->nip) == BUG_TRAP_TYPE_WARN) {
regs->nip += 4;
return;
}
@@ -818,6 +771,31 @@ void __kprobes program_check_exception(struct pt_regs *regs)
local_irq_enable();
+#ifdef CONFIG_MATH_EMULATION
+ /* (reason & REASON_ILLEGAL) would be the obvious thing here,
+ * but there seems to be a hardware bug on the 405GP (RevD)
+ * that means ESR is sometimes set incorrectly - either to
+ * ESR_DST (!?) or 0. In the process of chasing this with the
+ * hardware people - not sure if it can happen on any illegal
+ * instruction or only on FP instructions, whether there is a
+ * pattern to occurences etc. -dgibson 31/Mar/2003 */
+ switch (do_mathemu(regs)) {
+ case 0:
+ emulate_single_step(regs);
+ return;
+ case 1: {
+ int code = 0;
+ code = __parse_fpscr(current->thread.fpscr.val);
+ _exception(SIGFPE, regs, code, regs->nip);
+ return;
+ }
+ case -EFAULT:
+ _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
+ return;
+ }
+ /* fall through on any other errors */
+#endif /* CONFIG_MATH_EMULATION */
+
/* Try to emulate it if we should. */
if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
switch (emulate_instruction(regs)) {
@@ -931,18 +909,39 @@ void SoftwareEmulation(struct pt_regs *regs)
#ifdef CONFIG_MATH_EMULATION
errcode = do_mathemu(regs);
+
+ switch (errcode) {
+ case 0:
+ emulate_single_step(regs);
+ return;
+ case 1: {
+ int code = 0;
+ code = __parse_fpscr(current->thread.fpscr.val);
+ _exception(SIGFPE, regs, code, regs->nip);
+ return;
+ }
+ case -EFAULT:
+ _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
+ return;
+ default:
+ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+ return;
+ }
+
#else
errcode = Soft_emulate_8xx(regs);
-#endif
- if (errcode) {
- if (errcode > 0)
- _exception(SIGFPE, regs, 0, 0);
- else if (errcode == -EFAULT)
- _exception(SIGSEGV, regs, 0, 0);
- else
- _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
- } else
+ switch (errcode) {
+ case 0:
emulate_single_step(regs);
+ return;
+ case 1:
+ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+ return;
+ case -EFAULT:
+ _exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
+ return;
+ }
+#endif
}
#endif /* CONFIG_8xx */
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-01-21 09:06:37 +0000